U.S. patent application number 17/332107 was filed with the patent office on 2021-10-07 for distance measurement sensor and distance measurement method.
This patent application is currently assigned to KOITO MANUFACTURING CO., LTD.. The applicant listed for this patent is KOITO MANUFACTURING CO., LTD.. Invention is credited to Toru NAGASHIMA.
Application Number | 20210311191 17/332107 |
Document ID | / |
Family ID | 1000005639643 |
Filed Date | 2021-10-07 |
United States Patent
Application |
20210311191 |
Kind Code |
A1 |
NAGASHIMA; Toru |
October 7, 2021 |
DISTANCE MEASUREMENT SENSOR AND DISTANCE MEASUREMENT METHOD
Abstract
A scanning device includes a motor and a mirror attached to the
motor and configured to reflect emitted light of a light source.
The scanning device is configured to scan probe light, which is
reflected light reflected by the mirror, according to the rotation
of the motor. A photosensor detects return light, which is light
reflected from a point on an object. A processor detects the
distance to the point on the object based on the output of the
photosensor. A distance measurement sensor changes the angular
resolution according to the distance to the object.
Inventors: |
NAGASHIMA; Toru;
(Shizuoka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOITO MANUFACTURING CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
KOITO MANUFACTURING CO.,
LTD.
Tokyo
JP
|
Family ID: |
1000005639643 |
Appl. No.: |
17/332107 |
Filed: |
May 27, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/JP2019/045094 |
Nov 18, 2019 |
|
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17332107 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01S 17/08 20130101;
G02B 26/122 20130101; G01S 7/4817 20130101; G02B 26/105
20130101 |
International
Class: |
G01S 17/08 20060101
G01S017/08; G02B 26/10 20060101 G02B026/10; G01S 7/481 20060101
G01S007/481; G02B 26/12 20060101 G02B026/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2018 |
JP |
2018-225761 |
Claims
1. A distance measurement sensor comprising: a light source; a
scanning device comprising a motor and a mirror attached to the
motor and structured to reflect emitted light of the light source,
wherein the scanning device is structured such that scan probe
light, which is light reflected by the mirror, can be scanned
according to a rotation of the motor; a photosensor structured to
detect return light, which is the probe light reflected from a
point on an object; and a processor structured to detect a distance
to the point on the object based on an output of the photosensor,
wherein an angular resolution in a scan direction is changed
according to a distance to the object.
2. The distance measurement sensor according to claim 1, wherein a
rotational speed of the motor is changed according to the distance
to the object.
3. The distance measurement sensor according to claim 1, wherein a
distance measurement period is changed according to the distance to
the object.
4. The distance measurement sensor according to claim 1, wherein
the angular resolution is changed in a discrete manner according to
the distance to the object.
5. The distance measurement sensor according to claim 1, wherein
the angular resolution is controlled for every detected object.
6. An automotive lamp comprising: the distance measurement sensor
according to claim 1; a variable light distribution lamp; and a
controller structured to control the variable light distribution
lamp according to an output of the distance measurement sensor.
7. A distance measurement method comprising: rotating a motor to
which a mirror is attached; irradiating light to the mirror so as
to scan light reflected from the mirror; detecting, by means of a
photosensor, return light which is light reflected from an object;
detecting, by calculation, a distance to a point on the object
based on an output of the photosensor; and changing an angular
resolution according to the distance to the object.
Description
BACKGROUND
1. Technical Field
[0001] The present invention relates to a distance measurement
technique.
2. Description of the Related Art
[0002] Candidates of vehicle sensors include Light Detection and
Ranging, Laser Imaging Detection and Ranging (LiDAR), cameras,
millimeter-wave radar, ultrasonic sonar, and so forth. In
particular, LiDAR has advantages as compared with other sensors.
Examples of such advantages include: (i) an advantage of being
capable of recognizing an object based on point cloud data; (ii) an
advantage in employing active sensing, which is capable of
providing high-precision detection even in bad weather conditions;
(iii) an advantage of providing wide-range measurement; etc.
Accordingly, LiDAR is anticipated to become mainstream in vehicle
sensing systems.
[0003] Currently, commercially available LiDARs have a problem of
an extremely high cost. Accordingly, in some cases, it is difficult
to employ such a high-cost LiDAR depending on the kind of
automobile or the usage thereof.
SUMMARY
[0004] The present disclosure has been made in view of such a
situation.
[0005] An embodiment of the present disclosure relates to a
distance measurement sensor. The distance measurement sensor
includes: a light source; a scanning device including a motor and a
mirror attached to the motor and structured to reflect emitted
light of the light source, in which the scanning device is
structured such that scan probe light, which is light reflected by
the mirror, can be scanned according to the rotation of the motor;
a photosensor structured to detect return light, which is the probe
light reflected by an object; and a processor structured to detect
the distance to a point on the object based on the output of the
photosensor. The angular resolution in the scan direction is
changed according to the distance to the object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments will now be described, by way of example only,
with reference to the accompanying drawings which are meant to be
exemplary, not limiting, and wherein like elements are numbered
alike in several Figures, in which:
[0007] FIG. 1 is a block diagram showing a distance measurement
sensor according to an embodiment;
[0008] FIG. 2 is a diagram showing point cloud data acquired with a
constant angular resolution .DELTA..theta.;
[0009] FIG. 3 is a diagram showing point cloud data acquired with a
variable angular resolution .DELTA..theta.;
[0010] FIGS. 4A and 4B are diagrams each showing a relation between
the distance d to an object and the angular resolution
.DELTA..theta.;
[0011] FIG. 5 is a diagram showing a relation between the distance
measurement range and the angular resolution .DELTA..theta.;
[0012] FIG. 6 is a diagram showing an example of the control of the
angular resolution .DELTA..theta.;
[0013] FIG. 7 is a block diagram showing the distance measurement
sensor according to an example 1;
[0014] FIG. 8 is a time chart showing the control of the angular
resolution .DELTA..theta. according to the example 1;
[0015] FIG. 9 is a time chart showing the control of the angular
resolution .DELTA..theta. according to an example 2;
[0016] FIG. 10 is a block diagram showing an automobile provided
with the distance measurement sensor;
[0017] FIG. 11 is a block diagram showing an automotive lamp
provided with the distance measurement sensor.
DETAILED DESCRIPTION
Overview of the Embodiments
[0018] An outline of several example embodiments of the disclosure
follows. This outline is provided for the convenience of the reader
to provide a basic understanding of such embodiments and does not
wholly define the breadth of the disclosure. This outline is not an
extensive overview of all contemplated embodiments, and is intended
to neither identify key or critical elements of all embodiments nor
to delineate the scope of any or all aspects. Its sole purpose is
to present some concepts of one or more embodiments in a simplified
form as a prelude to the more detailed description that is
presented later.
[0019] An embodiment disclosed in the present specification relates
to a distance measurement sensor. The distance measurement sensor
includes a light source, a scanning device, a photosensor, and a
processor. The scanning device includes a motor and a mirror
attached to the motor and structured to reflect emitted light of
the light source. The scanning device is structured such that scan
probe light, which is light reflected by the mirror, can be scanned
according to the rotation of the motor. The photosensor detects
return light that is the probe light reflected from a point on an
object. The angular resolution in the scan direction is changed
according to the distance to the object.
[0020] With this embodiment, the resolution in the scan direction
(e.g., horizontal direction) is dynamically changed according to
the distance to the object. This allows the shape of an object
located at a farther position to be detected with high
precision.
[0021] Also, the rotational speed of the motor may be changed
according to the distance to the object. Instead of or in addition
to such an arrangement, the distance measurement period may be
changed according to the distance to the object.
[0022] Another embodiment of the present disclosure relates to an
automotive lamp. The automotive lamp includes: any one from among
the above-described distance measurement sensors; a variable light
distribution lamp; and a controller structured to control the
variable light distribution lamp according to the output of the
distance measurement sensor.
EMBODIMENTS
[0023] Description will be made below regarding the present
disclosure based on preferred embodiments with reference to the
drawings. The same or similar components, members, and processes
are denoted by the same reference numerals, and redundant
description thereof will be omitted as appropriate. The embodiments
have been described for exemplary purposes only, and are by no
means intended to restrict the present disclosure. Also, it is not
necessarily essential for the present invention that all the
features or a combination thereof be provided as described in the
embodiments.
[0024] FIG. 1 is a block diagram showing a distance measurement
sensor 100 according to an embodiment. The distance measurement
sensor 100 is configured as a LiDAR (Light Detection and Ranging),
including a light source 110, a scanning device 120, a photosensor
130, and a processor 140. The light source 110 emits light L1
having an infrared spectrum, for example. The emitted light L1 of
the light source 110 may be modulated with respect to time.
[0025] The scanning device 120 includes a motor 122 and one or
multiple mirrors (which will be also referred to as "blades") 126.
The mirrors 126 are configured to have a fan-shaped structure. The
mirrors 126 are attached to a rotational shaft 124 of the motor 122
such that they reflect the emitted light L1 of the light source
110. The emission angle (which will also be referred to as a "scan
angle") .theta. of probe light L2, which is light reflected from
the mirrors 126, changes according to the position of the mirrors
126 (i.e., rotational angle .PHI. of the motor). Accordingly, by
rotationally driving the motor 122, the probe light L2 can be
scanned in the .theta. direction ranging between .theta..sub.MIN
and .theta..sub.MAX. It should be noted that, in a case in which
the number of mirrors 126 thus provided is two, one half-rotation
of the motor 122 (mechanical angle of 180 degrees) corresponds to a
single scan. Accordingly, the probe light L2 is scanned twice every
time the motor 122 is rotated once. It should be noted that the
number of the mirrors 126 is not restricted in particular.
[0026] The rotational angle .PHI. of the motor 122 can be detected
by means of a position detection mechanism such as a Hall sensor,
optical encoder, or the like. Accordingly, the scan angle .theta.
at each time point can be obtained based on the rotational angle
.PHI..
[0027] The photosensor 130 detects return light L3 reflected at a
point P on an object OBJ. The processor 140 detects the distance to
the point P on the object OBJ based on the output of the
photosensor 130. The distance detection method or algorithm is not
restricted in particular. Rather, known techniques may be employed.
For example, the delay time from the emission of the probe light L2
to the reception of the return light by means of the photosensor
130, i.e., the time of flight (TOF), may be measured so as to
acquire the distance.
[0028] The above is the basic configuration of the distance
measurement sensor 100. Next, description will be made regarding
the operation thereof. The motor 122 is rotationally driven so as
to change the scan angle .theta. of the probe light L2 in the order
of .theta..sub.1, .theta..sub.2, . . . . In this operation, the
distance r.sub.i to the point P.sub.i on the surface of the object
OBJ is measured at each scan angle .theta..sub.1 (i=1, 2, With
this, data (point cloud data) formed of data pairs each configured
as a pair of the scan angle .theta..sub.1 and the corresponding
distance r.sub.i, can be acquired.
[0029] With such a distance measurement sensor 100, the scanning
device 120 can be configured as a combination of the motor 122
configured as a commonplace motor and the mirrors 126 arranged in a
fan structure. This provides the distance measurement sensor 100
with a reduced cost.
[0030] Next, description will be made regarding other features of
the distance measurement sensor 100. FIG. 2 is a diagram showing
the point cloud data acquired in measurement with a constant
angular resolution .DELTA..theta.. An object OBJ1 is located at a
position that is relatively nearer to the distance measurement
sensor 100. In contrast, an object OBJ2 is located at a position
that is relatively farther from the distance measurement sensor
100.
[0031] In a case of measurement with a constant angular resolution
.DELTA..theta., reflected light data is acquired for a relatively
larger number of points P1 with respect to the object OBJ1 at a
position nearer to the distance measurement sensor 100. However, as
the distance to the object becomes larger, the number of the points
P for which the reflected light data is acquired becomes smaller.
That is to say, as the distance to the object becomes larger, the
difficulty of judging its shape becomes higher.
[0032] In order to solve such a problem, an approach can be
employed in which the angular resolution .DELTA..theta. is designed
to be very fine so as to provide sufficient resolution for an
object at the farthest position within the distance measurement
range of the distance measurement sensor 100. However, such an
approach involves an enormous number of points of point cloud data
acquired in a single scan. This requires the processor 140 to
support an enormous amount of calculation, leading to reduction of
the scanning rate. In order to provide the scanning rate required
by an application, such an arrangement requires the processor 140
to be configured as a high-cost, high-performance processor. This
does not meet a demand for the distance measurement sensor 100 to
be provided with a low cost.
[0033] In order to solve such a problem, with the present
embodiment, the angular resolution .DELTA..theta. is designed to be
dynamically changed according to the distance d to the object OBJ.
FIG. 3 is a diagram showing the point cloud data acquired with a
variable angular resolution .DELTA..theta.. When the object OBJ2 to
be measured is located at a farther position, the angular
resolution .DELTA..theta. is adjusted to a higher resolution. With
this, reflected light data is acquired for four points with respect
to the object OBJ2 at a farther position. This allows the shape
judgement to be made even for the object OBJ2 located at a farther
position.
[0034] From another viewpoint, when the object OBJ1 is located at a
nearer position, the angular resolution .DELTA..theta. is adjusted
to a lower resolution so as to reduce the number of points of point
cloud data. This allows the scanning rate required for an
application to be supported even in a case of employing a low-cost,
relatively low-performance processor as the processor 140.
[0035] FIGS. 4A and 4B are diagrams each showing the relation
between the distance d to the object and the angular resolution
.DELTA..theta.. For example, let us consider an example in which a
spatial resolution of .DELTA.x is designed in the scan direction
regardless of the distance d to the object. In this case, it is
sufficient if the following Expression (1) is satisfied.
Accordingly, the relation expression between .DELTA..theta. and d
is represented by Expression (2).
dsin(.DELTA..theta.)=.DELTA.x (1)
.DELTA..theta.=arcsin(.DELTA.x/d) (2)
[0036] FIGS. 4A and 4B are diagrams each showing the relation
between .DELTA..theta. and d with .DELTA.x as 0.2 m. Specifically,
FIG. 4 shows the relation with the horizontal axis as a linear
scale. FIG. 4B shows the relation with the horizontal axis as a
logarithmic scale.
[0037] The angular resolution .DELTA..theta. may be held in the
form of a function of the distance d, and the angular resolution
.DELTA..theta. may be calculated by the processor 140.
Alternatively, a table that represents the relation between the
distance d and the angular resolution .DELTA..theta. may be held,
and the angular resolution .DELTA..theta. may be acquired by
referring to the table.
[0038] Instead of such an example as shown in FIGS. 4A and 4B in
which the angular resolution .DELTA..theta. is continuously changed
according to the distance d to the object OBJ, the angular
resolution .DELTA..theta. may be changed in a discrete manner as
described below. That is to say, the overall distance measurement
range is divided into m multiple ranges R.sub.1 through R.sub.m,
and the angular resolutions .DELTA..theta..sub.1 through
.DELTA..theta..sub.m may be determined for each range. FIG. 5 is a
diagram showing the relation between the distance measurement range
and the angular resolution .DELTA..theta.. FIG. 5 shows an example
in which m=3. However, the number of the divided ranges is not
restricted in particular. For example, the division number m may be
2 or 4 or more.
[0039] The distance d to the object OBJ can be detected based on
the distance r to a typical point P on the surface of the object
OBJ. As the typical point, the point at which the reflected light
data was first acquired may be selected. Alternatively, multiple
points may be selected as the typical points. In this case, the
average value of the distances to the multiple typical points may
be employed as the distance d to the object OBJ.
[0040] The resolution .DELTA..theta. may be dynamically changed in
one scanning period. For example, the angular resolution
.DELTA..theta. may be updated every time a new object OBJ is
detected. FIG. 6 is a diagram showing an example of the control of
the angular resolution .DELTA..theta.. The horizontal axis
represents the scan angle .theta., which can be associated with the
direction of time progression. The upper graph shows the distance
r. The lower graph shows the angular resolution .DELTA..theta..
FIG. 6 shows graphs over two scanning periods.
[0041] Let us consider a situation in which the object OBJ1 is
positioned within the range R.sub.1, and the object OBJ2 is
positioned within the range R.sub.2. Initially, the angular
resolution .DELTA..theta. is set to an initial value
.theta..sub.0.
[0042] The distance r.sub.i to the first point P.sub.i is measured
on the object OBJ1. In this stage, assuming that the distance
r.sub.i is the same as the distance d1 to the object OBJ1,
judgement is made that the object OBJ1 is positioned within the
range R.sub.1. Accordingly, after the angular resolution
.DELTA..theta. is set to a larger value .DELTA..theta..sub.1, the
scanning progresses.
[0043] Subsequently, the distance r.sub.j to the first point
P.sub.j is measured on the object OBJ2. In this stage, based on the
distance r.sub.j, i.e., assuming that the distance r.sub.j is the
same as the distance d2 to the object OBJ2, judgement is made that
the object OBJ2 is positioned within the range R.sub.2.
Accordingly, after the angular resolution .DELTA..theta. is set to
a smaller value .DELTA..theta..sub.2, the scanning progresses.
[0044] After the scan angle .theta. reaches .theta..sub.MAX, the
measurement proceeds to the next scanning period. In this stage,
the angular resolution .DELTA..theta. is returned to
.theta..sub.MIN.
[0045] The distance r.sub.k to the first point P.sub.k is measured
on the object OBJ1. In this stage, assuming that the distance
r.sub.k is the same as the distance d1 to the object OBJ1,
judgement is made that the object OBJ1 is positioned within the
range R.sub.1. Accordingly, after the angular resolution
.DELTA..theta. is set to .DELTA..theta..sub.1, the scanning
progresses.
[0046] Subsequently, the distance r.sub.1 to the first point
P.sub.1 is measured on the object OBJ2. In this stage, based on the
distance r.sub.1, i.e., assuming that the distance r.sub.1 is the
same as the distance d2 to the object OBJ2, judgement is made that
the object OBJ2 is positioned within the range R.sub.2.
Accordingly, after the angular resolution .DELTA..theta. is set to
.DELTA..theta..sub.2, the scanning progresses.
[0047] It should be noted that, when significant reflected light
data cannot be acquired in a given range, the angular resolution
.DELTA..theta. may be set to a larger value. This allows the number
of points of the point cloud data to be reduced, thereby allowing
the calculation load of the processor 140 to be reduced.
[0048] Next, description will be made with reference to several
examples regarding a method for controlling the angular resolution
.DELTA..theta..
Example 1
[0049] FIG. 7 is a block diagram showing a distance measurement
sensor 100A according to an example 1. The distance measurement
sensor 100A is configured to dynamically change the rotational
speed of the motor 122 according to the distance d to the object
OBJ.
[0050] The processor 140 supplies timing signals S1 and S2 to the
light source 110 and the photosensor 130, respectively, in order to
maintain the distance measurement period (sampling rate) Tr at a
constant value.
[0051] The light source 110 includes a light-emitting element 112
and a lighting circuit 114. The lighting circuit 114 turns on the
light-emitting element 112 in synchronization with the timing
signal S1. The photosensor 130 measures the return light L3 in
synchronization with the timing signal S2.
[0052] The processor 140 acquires the TOF based on an output S4 of
the photosensor 130. The distance measurement sensor 100A may
include a position sensor 129 that detects the position of a rotor
of the motor 122 (rotational angle .PHI. of the motor). The
processor 140 may acquire the current scan angle .theta. based on
an output S5 of the position sensor 129.
[0053] The processor 140 determines the angular resolution
.DELTA..theta. based on the distance d to the object OBJ.
Subsequently, the processor 140 outputs a rotational speed command
S3 that corresponds to the angular resolution .DELTA..theta. to a
motor driving circuit 128. The motor driving circuit 128
rotationally drives the motor 122 with a rotational speed that
corresponds to the rotational speed command S3.
[0054] The above is the configuration of the distance measurement
sensor 100A. Next, description will be made regarding the operation
thereof. FIG. 8 is a time chart showing a control operation for
controlling the angular resolution .DELTA..theta. according to the
example 1. A distance measurement timing occurs for every
predetermined period Tr. During a period from t.sub.0 to t.sub.1,
the motor rotational speed is set to a first value v.sub.1. In this
period, the rotational angle .PHI. is changed with a first slope.
For simplification of description, assuming that the scan angle
changes in proportion to the motor rotational angle .PHI., the scan
angle .theta. is increased with a given slope .alpha..sub.1. In
this case, the angular resolution .DELTA..theta..sub.1 is
represented by .alpha..sub.1.times.Tr.
[0055] During the period from t.sub.1 to t.sub.2, the rotational
speed of the motor is set to a second value v.sub.2 that is smaller
than the first value v.sub.1. In this period, the motor rotational
angle .PHI. is changed with a second slope. In this case, the scan
angle .theta. is increased with a relatively small slope
.alpha..sub.2 (<.alpha..sub.1). The corresponding angular
resolution .DELTA..theta..sub.2 is represented by
.alpha..sub.2.times.Tr.
[0056] As described above, with the example 1, by controlling the
motor rotational speed, the angular resolution .DELTA..theta. can
be controlled.
[0057] It should be noted that a stepping motor is employed as the
motor 122. In this case, the processor 140 is able to control the
rotational speed according to the frequency of pulses supplied to
the motor 122. Specifically, this arrangement allows the rotational
angle to be controlled according to the number of pulses thus
supplied. With such an arrangement employing such a stepping motor,
an open-loop control operation can be supported, thereby allowing
the position sensor 129 to be omitted.
Example 2
[0058] In an example 2, the distance measurement sensor 100 is
configured to change the distance measurement period Tr while
maintaining the motor rotational speed at a constant value. FIG. 9
is a time chart with respect to the control operation for
controlling the angular resolution .DELTA..theta. according to the
example 2.
[0059] The motor rotational speed is maintained at a constant value
v.sub.0 over the entire scanning period T.sub.SCAN. Accordingly,
the scan angle .theta. is increased with a constant slope
.alpha..sub.0.
[0060] During a period from t.sub.0 to t.sub.1, the distance
measurement period Tr is set to a relatively long period, i.e., a
first value Tr.sub.i. In this period, the angular resolution
.DELTA..theta..sub.1 is represented by
.alpha..sub.0.times.Tr.sub.1.
[0061] During a period from t.sub.1 to t.sub.2, the distance
measurement period Tr is set to a relatively short period, i.e., a
second value Tr.sub.2. In this period, the angular resolution
.DELTA..theta..sub.2 is represented by
.alpha..sub.0.times.Tr.sub.2.
[0062] As described above, by changing the distance measurement
period Tr, the angular resolution .DELTA..theta. can be
controlled.
Example 3
[0063] An example 3 is configured as a combination of the examples
1 and 2. Specifically, both the motor rotational speed and the
distance measurement period Tr are changed. This allows the angular
resolution .DELTA..theta. to be adjusted.
Usage
[0064] FIG. 10 is a block diagram showing an automobile provided
with the distance measurement sensor 100. An automobile 300 is
provided with headlamps 302L and 302R. At least one from among the
headlamps 302L and 302R is provided with the distance measurement
sensor 100 as a built-in component. Each headlamp 302 is positioned
at a frontmost end of the vehicle body, which is most advantageous
as a position where the distance measurement sensor 100 is to be
installed for detecting an object in the vicinity.
[0065] FIG. 11 is a block diagram showing an automotive lamp 200
including the distance measurement sensor 100. The automotive lamp
200 forms a lamp system 310 together with an in-vehicle ECU 304.
The automotive lamp 200 includes a light source 202, a lighting
circuit 204, and an optical system 206. Furthermore, the automotive
lamp 200 is provided with an object detection system 400. The
object detection system 400 includes the above-described distance
measurement sensor 100 and a processing device 410. The processing
device 410 judges the presence or absence and the kind of an object
OBJ in front of the vehicle based on point cloud data acquired by
the distance measurement sensor 100. The processing device 410 may
include an identifying device that operates based on a trained
model acquired by machine learning.
[0066] Also, the information with respect to the object OBJ
detected by the processing device 410 may be used to support the
light distribution control operation of the automotive lamp 200.
Specifically, a lamp ECU 208 generates a suitable light
distribution pattern based on the information with respect to the
kind of the object OBJ and the position thereof thus generated by
the processing device 410. The lighting circuit 204 and the optical
system 206 operate so as to provide the light distribution pattern
generated by the lamp ECU 208.
[0067] Also, the information with respect to the object OBJ
detected by the processing device 410 may be transmitted to the
in-vehicle ECU 304. The in-vehicle ECU may support autonomous
driving based on the information thus transmitted.
[0068] Description has been made above regarding the present
invention with reference to the embodiments. The above-described
embodiments have been described for exemplary purposes only, and
are by no means intended to be interpreted restrictively. Rather,
it can be readily conceived by those skilled in this art that
various modifications may be made by making various combinations of
the aforementioned components or processes, which are also
encompassed in the technical scope of the present invention.
Description will be made below regarding such modifications.
Modification 1
[0069] Description has been made in the embodiment regarding the
distance measurement sensor 100 that supports a single scan line.
Also, the distance measurement sensor 100 may support multiple scan
lines.
Modification 2
[0070] Description has been made in the embodiment regarding an
example in which the angular resolution .DELTA..theta. is designed
such that the spatial resolution .DELTA.x in the scan direction is
maintained to be as uniform as possible regardless of the distance
d to the object. However, the present invention is not restricted
to such an example. Also, the spatial resolution .DELTA.x may be
designed to be changed according to the distance d to the
object.
Example 3
[0071] Description has been made in the embodiment regarding an
example in which the distance measurement sensor 100 is mounted on
a lamp as an example application of the distance measurement sensor
100. However, the usage of the distance measurement sensor 100 is
not restricted to such an example. Rather, the distance measurement
sensor 100 is applicable to various kinds of usages that do not
require the level of performance of high-cost commercially
available LiDAR.
[0072] Description has been made regarding the present invention
with reference to the embodiments using specific terms. However,
the above-described embodiments show only an aspect of the
mechanisms and applications of the present invention. Rather,
various modifications and various changes in the layout can be made
without departing from the spirit and scope of the present
invention defined in appended claims.
* * * * *